As portable electronic devices become smaller, and the number of functions performed by a given device increases, it has become a significant challenge to design a user interface that allows users to easily interact with such multifunction devices. This challenge is particularly significant for handheld portable devices, which have much smaller screens than desktop or laptop computers. This situation is unfortunate because the user interface is the gateway through which users receive not only content but also responses to user actions or behaviors, including user attempts to access a device's features, tools, and functions. Some portable communication devices (e.g., mobile telephones, sometimes called mobile phones, cell phones, cellular telephones, smart phones or the like) have resorted to adding more pushbuttons, increasing the density of push buttons, overloading the functions of pushbuttons, or using complex menu systems to allow a user to access, store and manipulate data. These conventional user interfaces often result in complicated key sequences and menu hierarchies that must be memorized by the user.
Many conventional user interfaces, such as those that include physical pushbuttons, are also inflexible. This is unfortunate because it may prevent a user interface from being configured and/or adapted by either an application running on the portable device or by users. When coupled with the time consuming requirement to memorize multiple key sequences and menu hierarchies, and the difficulty in activating a desired pushbutton, such inflexibility is frustrating to most users.
In particular, when a conventional user interface on a portable device is used to display a portion of an electronic document, a portion of a list of items, or a portion of any other textual or graphic element, a user may not be able to tell the position in the document, list or other element of the displayed portion. The user also may not be able to tell what fraction of the document or list corresponds to the displayed portion. Lacking this knowledge, the user may find viewing and navigating the document or list to be confusing and frustrating. In some portable devices, scroll bars are used to indicate the position in the document or list of the displayed portion. But scroll bars are commonly fixed user interface features that take up valuable display screen area on an already small display screen. In addition, scroll bars are sometimes used both for indicating the position in the document and for receiving scroll commands from the user. This dual functionality is often cumbersome in a device with a touch screen, where more intuitive and convenient scrolling means are desired and possible—such as finger swipes on arbitrary portions of the screen.
Accordingly, there is a need for portable multifunction devices with more intuitive and convenient user interfaces for navigating portions of electronic documents, lists of items and/or the like, that are easy to use and that do not reduce the screen area available for the display of documents, lists, and/or other content. Such interfaces increase the effectiveness, efficiency and user satisfaction with portable multifunction devices.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.